Neuroblastoma, the most common extracranial solid tumour in children, may undergo spontaneous differentiation or regression, but the majority of metastatic
neuroblastomas have poor prognosis despite intensive treatment.
Retinoic acid and its analogues regulate growth and differentiation of
neuroblastoma cells in vitro, and 13-cis
retinoic acid has shown activity against human
neuroblastomas in vivo.
Fenretinide [N-(4-hydroxyphenyl)
retinamide] has been identified as a synthetic
retinoid able to induce apoptosis of numerous malignant cell lines in vitro, including
neuroblastoma. Furthermore, in animal models,
fenretinide has shown chemopreventive and therapeutic efficacy against several
malignancies without any obvious signs of toxicity. To investigate the anti-
neuroblastoma tumour growth effects of oral
fenretinide in vivo we used a human
neuroblastoma xenograft model. Nude rats with established
neuroblastoma xenograft tumours were treated orally with
fenretinide for 10 days. Five different doses of
fenretinide were used ranging from 2.5 to 75 mg/rat/day (10-300 mg/kg). Tumour volumes and toxic side effects were monitored during treatment and tumour weights were recorded at autopsy. In this study we found no significant anti-tumour growth effects of
fenretinide in vivo, when used as oral treatment of rats with established
neuroblastoma xenograft tumours. Furthermore, there were no intra tumoural differences in treated compared to untreated tumours. However, because of the promising results of
fenretinide on
neuroblastoma growth in vitro, further in vivo studies are warranted using other modalities of
drug administration.